fix grpc.tools version (#2074)

QiJune · web-flow · commit 4dbd8ab5dca7 · 2020-06-24T10:08:28.000+08:00
diff --git a/elasticdl/requirements.txt b/elasticdl/requirements.txt
@@ -1,4 +1,4 @@
-grpcio-tools
+grpcio-tools==1.29.0
 kubernetes==10.1.0
 docker
 pyrecordio>=0.0.6
